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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 477.9 km/sec
density: 3.0 protons/cm3
explanation | more data
Updated: Today at 2344 UT
X-ray Solar Flares
6-hr max: B5
1708 UT Jun04
24-hr: B7
1647 UT Jun04
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 04 Jun 11
Solar activity is low--at least temporarily---despite a large number of spots on the solar disk. Credit: SDO/HMI
Sunspot number: 122
What is the sunspot number?
Updated 03 Jun 2011

Spotless Days
Current Stretch: 0 days
2011 total: 1 day (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 820 days
Typical Solar Min: 486 days

Updated 03 Jun 2011

The Radio Sun
10.7 cm flux: 107 sfu
explanation | more data
Updated 03 Jun 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 5 storm
24-hr max: Kp= 5
explanation | more data
Interplanetary Mag. Field
Btotal: 16.9 nT
Bz: 12.1 nT south
explanation | more data
Updated: Today at 2345 UT
Coronal Holes: 04 Jun 11
A solar wind stream flowing from the indicated coronal hole could reach Earth on or about June 4th. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2011 Jun 04 2200 UTC
0-24 hr
24-48 hr
10 %
10 %
05 %
05 %
Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at: 2011 Jun 04 2200 UTC
0-24 hr
24-48 hr
40 %
30 %
20 %
10 %
05 %
01 %
High latitudes
0-24 hr
24-48 hr
45 %
35 %
25 %
20 %
05 %
05 %
Saturday, Jun. 4, 2011
What's up in space

Are we alone? Your iPhone has the answer. Download the all-new Drake Equation app to calculate the population of the Milky Way.

DrakeEQ for iPhone and iPad

MAGNETIC STORM WARNING: A sharp gust of solar wind hit Earth's magnetic field at approximately 20:30 UT on June 4th. High latitude sky watchers in both hemispheres should be alert for auroras. Aurora alerts: text, voice.

NOCTILUCENT CLOUDS OVER EUROPE: The 2011 noctilucent cloud (NLC) season has begun. For the past few nights, observers across northern Europe have spotted velvety, electric-blue tendrils rippling across the sunset sky. John Houghton sends this picture from Newtown Linford, Leicester, UK:

"This was the best display of noctilucent clouds I've seen to date," he says. "It was visible even before sunset."

NLCs are a summertime phenomenon. In the upper atmosphere, 80+ km high at the edge of space itself, tiny ice crystals nucleate around microscopic meteoroids and other aerosols; when the crystals catch the rays of the setting sun, they glow electric blue. Ironically, these highest and coldest of clouds form during the warmest months on the ground.

Noctilucent clouds first appeared in the 19th century after the eruption of super-volcano Krakatoa. At the time, people thought the clouds were caused by the eruption, but the clouds persisted long after Krakatoa's ash settled. In those early days, NLCs were a polar phenomenon, mainly seen in far-northern places such as Scandinavia or Alaska. In recent years they have intensified and spread with sightings as far south as Utah and Colorado. A NASA spacecraft named AIM is in orbit to investigate.

Readers, especially you at high latitudes, be alert for NLCs in the evenings ahead. Observing tips may be found in our 2009 Noctilucent Cloud Gallery.

more images: from Martin McKenna of Maghera, Co. Derry, N. Ireland; from Jesper Gronne of Silkeborg Denmark; from Paul Martin of Pigeon Top, Omagh, Northern Ireland; from Martin Stirland of Winterton On Sea, Norfolk, England; from John C McConnell of Maghaberry Northern Ireland.

SPRING CRESCENT: This evening, if you find yourself outside scanning the sunset sky for noctilucent clouds, be alert for the crescent Moon as well. You might see something like this:

Gary A. Becker of Coopersburg, Pennsylvania, took the picture on June 3rd. "Every evening is different," says Becker. "I have photographed young moons perhaps 100 times and no two images are duplicates. On June 3rd, a crystal clear day gave way to high clouds, which I thought were going to ruin the show. Happily, I was proven wrong."

more images: from Piotr Potepa of Chelmza, Poland; from KamilaM of Puławy, Poland; from Andrzej of Gdańsk, Poland; from Zsolt Szabolcs Szabó of Szolnok, Hungary; from Ignacio A. Rodriguez of Monterrey, Mexico; from Kevin Jung of Lowell Township, Michigan; from Fabiano Belisário Diniz of Curitiba, Brazil; from David Dickinson of Hudson, Florida;

Midnight Solar Eclipse Gallery
[NASA: A Rare Eclipse of the Midnight Sun]

April 2011 Aurora Gallery
[previous Aprils: 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002]

  Near Earth Asteroids
Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time.
On June 4, 2011 there were 1224 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2002 JC
Jun 1
57.5 LD
1.6 km
2009 BD
Jun 2
0.9 LD
10 m
2011 KE15
Jun 3
3.7 LD
16 m
2011 KV15
Jun 5
8.3 LD
25 m
2002 JB9
Jun 11
71.5 LD
3.2 km
2001 VH75
Jun 12
42.2 LD
1.1 km
2004 LO2
Jun 15
9.9 LD
48 m
2011 GA55
Jul 6
64.1 LD
1.0 km
2011 EZ78
Jul 10
37.3 LD
1.5 km
2003 YS117
Jul 14
73.9 LD
1.0 km
2007 DD
Jul 23
9.3 LD
31 m
2009 AV
Aug 22
49.7 LD
1.1 km
2003 QC10
Sep 18
50 LD
1.2 km
2004 SV55
Sep 19
67.5 LD
1.2 km
2007 TD
Sep 23
3.8 LD
58 m
Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.
  Essential web links
NOAA Space Weather Prediction Center
  The official U.S. government space weather bureau
Atmospheric Optics
  The first place to look for information about sundogs, pillars, rainbows and related phenomena.
Solar Dynamics Observatory
  Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever.
  3D views of the sun from NASA's Solar and Terrestrial Relations Observatory
Solar and Heliospheric Observatory
  Realtime and archival images of the Sun from SOHO.
Daily Sunspot Summaries
  from the NOAA Space Environment Center
  the underlying science of space weather
Conquest Graphics
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Science Central sponsor
  more links...
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